Body-mass index, waist-size, waist-hip ratio and cardiovascular risk factors in urban subejcts

Abstract

Background and objective: Influence of obesity as determinant of cardiovascular risk factors has not been well studied. To determine association of obesity, measured by body-mass index (BMI), waist-size or waist-hip ratio (WHR), with multiple risk factors in an urban Indian population we performed an epidemiological study.

Methods: Randomly selected adults > or = 20 years were studied using stratified sampling. Target sample was 1800 (men 960, women 840). 1123 subjects (response 62.4%) were evaluated and blood samples were available in 532 men and 559 women (n=1091, response 60.6%). Measurement of anthropometric variables, blood pressure, fasting blood glucose and lipids was performed. Atherosclerosis risk factors were determined using current guidelines. Pearson's correlation coefficients (r) of BMI, waist and WHR with various risk factors were determined. BMI was categorized into five groups: <20.0 Kg/m2, 20.0-22.9, 23.0-24.9, 25.0-29.9, and > or = 30 Kg/m2; waist size was divided into five groups and WHR into six groups in both men and women. Prevalence of cardiovascular risk factors, smoking, hypertension, diabetes, metabolic syndrome and dyslipidaemias was determined in each group and trends analyzed using least-squares regression.

Results: There is a significant positive correlation of BMI, waist-size and WHR with systolic BP (r= 0.46 to 0.13), diastolic BP (0.42 to 0.16), fasting glucose (0.15 to 0.26), and LDL cholesterol (0.16 to 0.03) and negative correlation with physical activity and HDL cholesterol (-0.22 to -0.08) in both men and women (p<0.01). With increasing BMI, waist-size and WHR, prevalence of hypertension, diabetes, and metabolic syndrome increased significantly (p for trend <0.05). WHR increase also correlated significantly with prevalence of high total and LDL cholesterol and triglycerides (p <0.05).

Conclusions: There is a continuous positive relationship of all markers of obesity (body-mass index, waist size and waist hip ratio) with major coronary risk factors- hypertension, diabetes and metabolic syndrome while WHR also correlates with lipid abnormalities.